1. Field of the Invention
This invention relates to an information recording medium, an information reproducing apparatus, an information reproducing method and an information recording method.
2. Description of the Related Art
An optical disk is used as an information recording medium for recording and reproducing information.
An art of increasing a total number of test write area (test area) in proportion to an increase of optical disk capacity is disclosed (See Patent document 1: Japanese Patent Laid-open Application No. 2001-273637). Namely, a test write area is disposed in an inner peripheral position, and its extension scaling factor is discretely set. Then, an SYNC pattern of an ATIP wobble signal is detected to determine the kind of the disc, and the total number of test areas (test write area) is determined.
An art of an optical disk capable of setting a spare area extendable to an outer peripheral side is disclosed (See Patent document 2: Japanese Patent No. 3090316). The position information of the extendable spare area is described in position information of a second spare area in a file entry area of the second spare area.